China Reports More Cases of Rare H7N9 Bird Flu

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Health officials in China reported Tuesday that four more people had developed H7N9 avian influenza, bringing to seven the total number who have been infected with this particular strain, which has never been seen before in humans. So far two men, aged 87 and 27, have died—both in Shanghai.

Although H7N9 has not been reported in people before, the larger H7 family of flu viruses has infected people previously—in the Netherlands, Italy, Canada, the U.S. and England. Those cases were associated with H7 outbreaks in poultry—and seemed to be milder in comparison to the latest cases.

The evidence to date suggests that this particular strain of H7N9 also got its start in poultry. One of the newly affected individuals reportedly was a Nanjing poultry butcher.

Authorities have found no evidence of the kind of easy transmission between people that would lead to larger outbreaks. But the fact that most of the people who have fallen ill apparently had no contact with each other suggests that there might be more than one source of infection.